This invention relates to stretcher suspension linkages.
The stretcher suspension linkages according to the present invention have particular application in the field of handling and supporting stretchers in, for example, ambulances but as will hereinafter become apparent can be used in other applications. For the purposes of disclosure of the stretcher suspension linkages reference will be primarily made to the linkages used in conjunction with an ambulance.
It is known to provide a stretcher suspension in an ambulance. The suspension not only retains and supports the stretcher but preferably provides isolation for stretcher-borne patients from ambulance floor vibration. A factor that must be taken into account with such suspensions is the different loadings which will arise from patients of differing weight. With known arrangements, either the suspension is not able to adapt to changes in load or is of a complex design in order to provide variation depending on load.
A further typical problem with stretcher suspensions in ambulances arises from the intrusion of the wheel arch into the space where stretchers are loaded. Consequently, it is not uncommon for an ambulance fitted with a stretcher suspension to only be able to carry one stretcher due to the need to position the suspension between the wheel arches.
A further requirement of stretcher suspension systems is to provide sufficient stiffness both laterally and in roll. Previous efforts to provide a suspension system which enables it to be fitted over an ambulance wheel arch so that two suspension/stretchers can be fitted in the ambulance (one against either side wall) have not been sufficiently stiff laterally and in roll.
An object of the present invention is thus to provide a linkage which is suitable for a stretcher suspension and which overcomes or goes some way to overcoming one or more of the disadvantages of known stretcher suspensions.
According to one broad aspect of the invention there is provided a linkage for a stretcher suspension, the linkage including link members arranged to permit a stretcher receiving member to move relative to a mounting base, the linkage including spring means, said base being arranged to be engageable at least in part about a protrusion in a surface with which the mounting base is mountable.